1. Field
Described herein is an item, such as a document, commercial packaging, and the like, comprised of a substrate having thereon a multiplicity of separate, non-touching printed markings, wherein the printed markings include both conductive printed markings and substantially non-conductive printed markings. Also described are methods of forming the item with security markings thereon and systems for forming and subsequently detecting the security markings. The different conductive and non-conductive regions on the substrate can be detected, for example by measuring the resistance or current of each printed marking. Advantages of the pattern of different conductive and non-conductive regions include being used as a security pattern of authenticity that cannot be replicated by standard office equipment such as photocopiers and scanners, and/or being used to encrypt information, for example in binary code form in the item.
2. Background Discussion
Conductive inks have been known to be used as an overt (that is, easy to see) security printing feature. The main advantage of the metallic inks is that they do not copy well using photocopiers and produce copies that are easily distinguishable from original documents. However, as it happens with any relatively old security printing technology, metallic ink technology is at risk of being counterfeited. Until recently, the technology has been relatively well protected due to a controlled supply/end-user chain. However, metallic inks are now currently being developed for many additional applications, such as printing antennas for RFIDs. This has resulted in a wide spread use, and much less controlled chain of distribution, of printable metallic inks. The inks may thus become more readily available to counterfeiters seeking to use the inks to replicate authentic items and documents.
It is estimated that worldwide counterfeiting and piracy cost brand owners over $500 billion every year. As a result, document and product security is of key importance for companies to protect their products and brand against counterfeiting. With the proliferation of digital printing, there is a need to protect printed documents, and document security needs to keep step.
Given that metallic inks represent a well established technology and are easy to implement, in order to continue to use them for security printing, novel methods of using metallic conductive ink are required.
There is thus a constant need for new technologies, systems and processes for providing security markings on an item, for example to encrypt information therein and/or to provide means for verification/authentication. Further, there is a need for new uses of conductive inks in security applications that will make it difficult for counterfeiters possessing the inks to easily replicate authentic items and documents.